A087803 Number of equations (order conditions) that must be satisfied to achieve order n in the construction of a Runge-Kutta method for the numerical solution of an ordinary differential equation.

1, 2, 4, 8, 17, 37, 85, 200, 486, 1205, 3047, 7813, 20299, 53272, 141083, 376464, 1011311, 2732470, 7421146, 20247374, 55469206, 152524387, 420807242, 1164532226, 3231706871, 8991343381, 16083734329, 53998409650